Reconfigurable and Self-optimizing Multicore Architectures. Presented by: Naveen Sundarraj
|
|
- Gwendolyn Dixon
- 5 years ago
- Views:
Transcription
1 Reconfigurable and Self-optimizing Multicore Architectures Presented by: Naveen Sundarraj 1 11/9/2012
2 OUTLINE Introduction Motivation Reconfiguration Performance evaluation Reconfiguration Self-optimization Performance evaluation Self-optimization Applications of RL in computer systems Conclusion 2 11/9/2012
3 Motivation Transistor size doubles every two years Moore s Law Chip Multiprocessors (CMPs) are attractive alternative to monolithic processors in translating transistor budgets into performance improvements. CMPs have performance limitations. Software overhead exploiting full potential of these chips. Need for software to expose exponentially increasing levels of TLP. 3 11/9/2012
4 Introduction To meet the challenges created by the adoption and scaling of multicore architectures, we explore versatile CMP architectures. Solution: A reconfigurable CMP substrate that can accommodate software at different stages of parallelization by allowing the granularity of the architecture to be changed at runtime. A self-optimizing memory controller that learns to optimize its scheduling policy on the fly, and adapts to changing memory reference streams and workload demands via runtime interaction with the system. 4 11/9/2012
5 Reconfiguration Reconfiguration is achieved through a novel reconfigurable mechanism called core fusion. Core fusion An architectural technique that empowers groups of relatively small and independent CMP cores with the ability to fuse into one large CPU on demand. Benefits: Support for software diversity. Support for smoother software evaluation. Single-design solution. Optimized for parallel code. Design-bug and hard-fault resilience. 5 11/9/2012
6 Core Fusion - design Challenges Increase in software complexity. Restructuring the base cores. Effective dynamic reconfiguration Hardware solution: Re-configurable distributed front-end and i-cache. Effective remote wake up mechanism Re-configurable, distributed load/store queue and d-cache Re-configurable, distributed ROB organization. 6 11/9/2012
7 Core Fusion - Architecture A bus connects L1 i- and d- caches and provides data coherence. On-chip memory controller reside on the other side of the bus. Cores can execute independently if desired and it is also possible to fuse groups of two or four cores to constitute larger cores. 7 11/9/2012
8 Modifications to achieve core fusion Front end Fetch mechanism and Instruction cache Branch prediction Return Address Stack Global History Registers Handling Fetch Stalls Collective Decode/Rename 8 11/9/2012
9 Fetch Mechanism and Instruction Cache Collective Fetch A small coordinating unit called the Fetch Management Unit (FMU) facilitates collective fetch. Fetch mechanism Each core fetches two instructions from its own i-cache every cycle, for a total of eight instructions. On an i-cache miss, an eight-word block is (a) delivered to the requesting core if it is operating independently, or (b) distributed across all four cores in a fused configuration to permit collective fetch. In order to support the above mechanism i-caches are made reconfigurable 9 11/9/2012
10 Reconfigurable i-cache Each i-cache has enough tags to organize data has enough tags to organize data in two-word sub blocks When running independently four such sub blocks and one tag make up a cache block. When fused, cache blocks span all four i-caches, with each i-cache holding one sub block and a replica of the cache block s tag /9/2012
11 Branches and subroutine calls prediction Each core accesses its own branch predictor and BTB. Branch predictor and BTB are indexed to accomplish maximum utilization while retaining simplicity. The indexing scheme achieves no loss in prediction accuracy /9/2012
12 Branch prediction mechanism In each cycle, every core that predicts a taken branch and also a branch misprediction sends the new target PC to the FMU. FMU selects the correct PC by giving priority to the oldest misprediction-redirect PC first and the youngest branchprediction PC last. On a misprediction, misspeculated instructions are squashed in all cores /9/2012
13 Branch prediction mechanism Core2 predicts branch B to be taken. After two cycles, all cores receive this prediction. They squash overfetched instructions, and adjust their PC /9/2012
14 Global History Register (GHR) Independent and uncoordinated history registers on each core may make it impossible for the branch predictor to learn of their correlation. Solution: GHR is replicated across all cores and updates are coordinated through FMU /9/2012
15 Return Address Stack The target PC of a subroutine call is sent to all the cores by the FMU. Core zero pushes the return address into it RAS. When a return instruction is encountered and communicated to the FMU, core zero pops its RAS and communicates the return address back through the FMU /9/2012
16 Handling fetch Stalls To preserve correct fetch alignment, all fetch engines must stall when fetch stall is encountered by one core. To accomplish this cores communicate stalls to the FMU, which in turn informs the other cores. Once all cores have been informed they all discard at the same time any overfetched instruction. Fetching is resumed in sync from the right PC /9/2012
17 Collective Decode /Rename After fetch, each core pre-decodes its instruction independently. Steering Management Unit (SMU) is used to rename all instructions in the fetch group. SMU consists of a global steering table to track the mapping of architectural registers to any core /9/2012
18 Back-end modifications to achieve core fusion Back end Wake-up and selection Reorder buffer and commit support Load/Store queue organization 18 11/9/2012
19 Wake-up and selection To support operand communication, a copy-out and copy-in queue are added to each core. When copy instructions reach the consumer core, they are placed in a FIFO copy-in queue. Every cycle, the scheduler considers the two copy instructions at the head, along with instructions in the conventional issue queue. Once issued, copies wake up their dependent instructions and update the physical register file /9/2012
20 Reorder buffer and commit support ROB 1 s head instruction pair is not ready to commit, which is communicated to the other ROBs. Pre-commit and conventional heads are spaced so that the message arrives just in time. Upon completion of ROB 1 s head instruction pair, a similar message is propagated, again arriving just in time to retire all four head instruction pairs in sync /9/2012
21 Load/Store queue organization In fused mode, a banked-by-address load-store queue(lsq) implementation is adopted. This keeps data coherent without requiring cache flushes and supports store forwarding and speculative loads. In the case of loads, if a bank misprediction is detected, the load queue entry is recycled and the load is sent to the correct one /9/2012
22 Dynamic Reconfiguration CMPs support for dynamic reconfiguration to respond to software changes (e.g., dynamic multiprogrammed environments or serial/parallel regions in a partially parallelized application) can greatly improve versatility, and thus performance. FUSE and SPLIT ISA instructions are used. FUSE operation: Application requests cores to be fused to execute sequential regions after executing parallel regions. SPLIT operation: In SPLIT operation, in-flight instructions are allowed to drain and enough copy instructions are generated /9/2012
23 Performance Evaluation Simulation done on parallel, evoking parallel and sequential work loads /9/2012
24 Performance Analysis 24 11/9/2012
25 Parallel application performance 25 11/9/2012
26 Why self-optimization? Self-Optimization Efficient utilization of off-chip DRAM bandwidth is a critical issue in designing cost-effective, high performance CMP platforms. Conventional memory controllers deliver relatively low performance because they often employ fixed, rigid access scheduling policies designed for average case application behavior. As a result they cannot learn and optimize the long term performance impact of their scheduling decisions, and cannot adopt their scheduling policies to dynamic workload behavior /9/2012
27 Reinforcement Learning (RL) Reinforcement learning is a field of machine learning that studies how autonomous agents situated in a stochastic environment can learn optimal control policies through interaction with their environment. RL provides a general framework for high performance, self optimizing memory controller design. The memory controller is designed as a RL agent whose goal is to learn automatically an optimal memory scheduling policy via interaction wit the rest of the system /9/2012
28 Advantages of RL based memory controller An RL-based memory controller takes as an input, parts of the system state and considers the long term performance impact of each action it can take. Anticipates the long-term consequences of its scheduling decisions, and continuously optimizes its scheduling policy based on this anticipation. Utilizes experience learned in previous system states to make good scheduling decisions in new, previously unobserved states. Adapts to dynamically changing workload demands and memory reference streams /9/2012
29 RL-Based DRAM schedulers Each DRAM cycle, the scheduler examines valid transaction queue entries. The scheduler maximizes DRAM utilization by choosing the command with the highest expected long term performance benefit. Scheduler first derives a state-action pair for each candidate command under the current system state and uses the information to calculate the corresponding Q-values. Scheduler implements its control policy by scheduling the command with the highest Q-value each DRAM cycle /9/2012
30 Performance Evaluation Performance comparison of in-order, FR-FCFS, RL based and optimistic memory controllers /9/2012
31 DRAM bandwidth utilization evaluation Comparison of DRAM bandwidth utilization of in-order, FR- FCFS, RL-based and optimistic controllers /9/2012
32 Applications of RL in computer systems Autonomic resource allocation decisions in data centers. Autonomous navigation and flight, helicopter control. Dynamic channel assignment in cellular networks. Processor and memory allocation in data centers. Routing in ad-hoc networks /9/2012
33 Performance Review For a 4-core CMP with single channel DDR2-800 memory subsystem(6.4 GB/s peak bandwidth). The RL based memory controller improves the performance of a set of parallel applications by 19% and DRAM bandwidth utilization by 22% over a state-of-the-art FR- FCFS scheduler. For a dual-channel subsystem, the RL-based scheduler delivers an additional 14% performance improvement. Thus performance gap between single-channel configuration and a dual-channel DDR2-800 subsystem wit twice peak bandwidth is reduced /9/2012
34 Conclusions Core fusion allows relatively simple CMP cores to dynamically fuse into larger, more powerful processors. It accommodates software diversity gracefully and dynamically adapts to changing demands by workloads. Core fusion adapts complexity-effective solutions for fetch, rename, execution, cache access and commit. RL based, self optimizing memory controller continuously and automatically adapts its DRAM scheduling policy based on its interaction with the system to optimize performance. RL based self optimizing memory controller efficiently utilizes the DRAM memory bandwidth available in CMP /9/2012
35 Questions? 35 11/9/2012
36 Thank you! 36 11/9/2012
Core Fusion: Accommodating Software Diversity in Chip Multiprocessors
Core Fusion: Accommodating Software Diversity in Chip Multiprocessors Authors: Engin Ipek, Meyrem Kırman, Nevin Kırman, and Jose F. Martinez Navreet Virk Dept of Computer & Information Sciences University
More informationCore Fusion: Accommodating Software Diversity in Chip Multiprocessors
Core Fusion: Accommodating Software Diversity in Chip Multiprocessors Engin İpek Meyrem Kırman Nevin Kırman José F. Martínez Computer Systems Laboratory Cornell University Ithaca, NY 4853 USA Submitted
More information6x86 PROCESSOR Superscalar, Superpipelined, Sixth-generation, x86 Compatible CPU
1-6x86 PROCESSOR Superscalar, Superpipelined, Sixth-generation, x86 Compatible CPU Product Overview Introduction 1. ARCHITECTURE OVERVIEW The Cyrix 6x86 CPU is a leader in the sixth generation of high
More informationLecture 8: Branch Prediction, Dynamic ILP. Topics: static speculation and branch prediction (Sections )
Lecture 8: Branch Prediction, Dynamic ILP Topics: static speculation and branch prediction (Sections 2.3-2.6) 1 Correlating Predictors Basic branch prediction: maintain a 2-bit saturating counter for each
More informationOutline. Exploiting Program Parallelism. The Hydra Approach. Data Speculation Support for a Chip Multiprocessor (Hydra CMP) HYDRA
CS 258 Parallel Computer Architecture Data Speculation Support for a Chip Multiprocessor (Hydra CMP) Lance Hammond, Mark Willey and Kunle Olukotun Presented: May 7 th, 2008 Ankit Jain Outline The Hydra
More informationModule 5: "MIPS R10000: A Case Study" Lecture 9: "MIPS R10000: A Case Study" MIPS R A case study in modern microarchitecture.
Module 5: "MIPS R10000: A Case Study" Lecture 9: "MIPS R10000: A Case Study" MIPS R10000 A case study in modern microarchitecture Overview Stage 1: Fetch Stage 2: Decode/Rename Branch prediction Branch
More information15-740/ Computer Architecture Lecture 23: Superscalar Processing (III) Prof. Onur Mutlu Carnegie Mellon University
15-740/18-740 Computer Architecture Lecture 23: Superscalar Processing (III) Prof. Onur Mutlu Carnegie Mellon University Announcements Homework 4 Out today Due November 15 Midterm II November 22 Project
More information250P: Computer Systems Architecture. Lecture 9: Out-of-order execution (continued) Anton Burtsev February, 2019
250P: Computer Systems Architecture Lecture 9: Out-of-order execution (continued) Anton Burtsev February, 2019 The Alpha 21264 Out-of-Order Implementation Reorder Buffer (ROB) Branch prediction and instr
More informationReorder Buffer Implementation (Pentium Pro) Reorder Buffer Implementation (Pentium Pro)
Reorder Buffer Implementation (Pentium Pro) Hardware data structures retirement register file (RRF) (~ IBM 360/91 physical registers) physical register file that is the same size as the architectural registers
More informationTutorial 11. Final Exam Review
Tutorial 11 Final Exam Review Introduction Instruction Set Architecture: contract between programmer and designers (e.g.: IA-32, IA-64, X86-64) Computer organization: describe the functional units, cache
More informationLecture: Out-of-order Processors. Topics: out-of-order implementations with issue queue, register renaming, and reorder buffer, timing, LSQ
Lecture: Out-of-order Processors Topics: out-of-order implementations with issue queue, register renaming, and reorder buffer, timing, LSQ 1 An Out-of-Order Processor Implementation Reorder Buffer (ROB)
More informationLecture 9: Dynamic ILP. Topics: out-of-order processors (Sections )
Lecture 9: Dynamic ILP Topics: out-of-order processors (Sections 2.3-2.6) 1 An Out-of-Order Processor Implementation Reorder Buffer (ROB) Branch prediction and instr fetch R1 R1+R2 R2 R1+R3 BEQZ R2 R3
More informationCS 152 Computer Architecture and Engineering. Lecture 12 - Advanced Out-of-Order Superscalars
CS 152 Computer Architecture and Engineering Lecture 12 - Advanced Out-of-Order Superscalars Dr. George Michelogiannakis EECS, University of California at Berkeley CRD, Lawrence Berkeley National Laboratory
More informationThe Alpha Microprocessor: Out-of-Order Execution at 600 Mhz. R. E. Kessler COMPAQ Computer Corporation Shrewsbury, MA
The Alpha 21264 Microprocessor: Out-of-Order ution at 600 Mhz R. E. Kessler COMPAQ Computer Corporation Shrewsbury, MA 1 Some Highlights z Continued Alpha performance leadership y 600 Mhz operation in
More information15-740/ Computer Architecture Lecture 5: Precise Exceptions. Prof. Onur Mutlu Carnegie Mellon University
15-740/18-740 Computer Architecture Lecture 5: Precise Exceptions Prof. Onur Mutlu Carnegie Mellon University Last Time Performance Metrics Amdahl s Law Single-cycle, multi-cycle machines Pipelining Stalls
More informationSuperscalar Processors
Superscalar Processors Superscalar Processor Multiple Independent Instruction Pipelines; each with multiple stages Instruction-Level Parallelism determine dependencies between nearby instructions o input
More informationAdvanced d Instruction Level Parallelism. Computer Systems Laboratory Sungkyunkwan University
Advanced d Instruction ti Level Parallelism Jin-Soo Kim (jinsookim@skku.edu) Computer Systems Laboratory Sungkyunkwan University http://csl.skku.edu ILP Instruction-Level Parallelism (ILP) Pipelining:
More informationROEVER ENGINEERING COLLEGE DEPARTMENT OF COMPUTER SCIENCE AND ENGINEERING
ROEVER ENGINEERING COLLEGE DEPARTMENT OF COMPUTER SCIENCE AND ENGINEERING 16 MARKS CS 2354 ADVANCE COMPUTER ARCHITECTURE 1. Explain the concepts and challenges of Instruction-Level Parallelism. Define
More informationComputer Systems Architecture
Computer Systems Architecture Lecture 12 Mahadevan Gomathisankaran March 4, 2010 03/04/2010 Lecture 12 CSCE 4610/5610 1 Discussion: Assignment 2 03/04/2010 Lecture 12 CSCE 4610/5610 2 Increasing Fetch
More informationThe Alpha Microprocessor: Out-of-Order Execution at 600 MHz. Some Highlights
The Alpha 21264 Microprocessor: Out-of-Order ution at 600 MHz R. E. Kessler Compaq Computer Corporation Shrewsbury, MA 1 Some Highlights Continued Alpha performance leadership 600 MHz operation in 0.35u
More informationEN164: Design of Computing Systems Topic 06.b: Superscalar Processor Design
EN164: Design of Computing Systems Topic 06.b: Superscalar Processor Design Professor Sherief Reda http://scale.engin.brown.edu Electrical Sciences and Computer Engineering School of Engineering Brown
More informationHardware-Based Speculation
Hardware-Based Speculation Execute instructions along predicted execution paths but only commit the results if prediction was correct Instruction commit: allowing an instruction to update the register
More informationCache Memory COE 403. Computer Architecture Prof. Muhamed Mudawar. Computer Engineering Department King Fahd University of Petroleum and Minerals
Cache Memory COE 403 Computer Architecture Prof. Muhamed Mudawar Computer Engineering Department King Fahd University of Petroleum and Minerals Presentation Outline The Need for Cache Memory The Basics
More informationChapter 4. Advanced Pipelining and Instruction-Level Parallelism. In-Cheol Park Dept. of EE, KAIST
Chapter 4. Advanced Pipelining and Instruction-Level Parallelism In-Cheol Park Dept. of EE, KAIST Instruction-level parallelism Loop unrolling Dependence Data/ name / control dependence Loop level parallelism
More informationComputer Architecture A Quantitative Approach, Fifth Edition. Chapter 3. Instruction-Level Parallelism and Its Exploitation
Computer Architecture A Quantitative Approach, Fifth Edition Chapter 3 Instruction-Level Parallelism and Its Exploitation Introduction Pipelining become universal technique in 1985 Overlaps execution of
More informationBranch Prediction & Speculative Execution. Branch Penalties in Modern Pipelines
6.823, L15--1 Branch Prediction & Speculative Execution Asanovic Laboratory for Computer Science M.I.T. http://www.csg.lcs.mit.edu/6.823 6.823, L15--2 Branch Penalties in Modern Pipelines UltraSPARC-III
More informationDual-Core Execution: Building A Highly Scalable Single-Thread Instruction Window
Dual-Core Execution: Building A Highly Scalable Single-Thread Instruction Window Huiyang Zhou School of Computer Science University of Central Florida New Challenges in Billion-Transistor Processor Era
More informationCNS Update. José F. Martínez. M 3 Architecture Research Group
1 CNS-0509404 Update José F. M 3 Architecture Research Group http://m3.csl.cornell.edu/ 2 Project s Recent Highlights Dynamic multicore reconfiguration/adaptation E. İpek, M. Kırman, N. Kırman, and J.F.
More informationE0-243: Computer Architecture
E0-243: Computer Architecture L1 ILP Processors RG:E0243:L1-ILP Processors 1 ILP Architectures Superscalar Architecture VLIW Architecture EPIC, Subword Parallelism, RG:E0243:L1-ILP Processors 2 Motivation
More informationEE382A Lecture 7: Dynamic Scheduling. Department of Electrical Engineering Stanford University
EE382A Lecture 7: Dynamic Scheduling Department of Electrical Engineering Stanford University http://eeclass.stanford.edu/ee382a Lecture 7-1 Announcements Project proposal due on Wed 10/14 2-3 pages submitted
More informationLecture 9: More ILP. Today: limits of ILP, case studies, boosting ILP (Sections )
Lecture 9: More ILP Today: limits of ILP, case studies, boosting ILP (Sections 3.8-3.14) 1 ILP Limits The perfect processor: Infinite registers (no WAW or WAR hazards) Perfect branch direction and target
More informationHardware-based speculation (2.6) Multiple-issue plus static scheduling = VLIW (2.7) Multiple-issue, dynamic scheduling, and speculation (2.
Instruction-Level Parallelism and its Exploitation: PART 2 Hardware-based speculation (2.6) Multiple-issue plus static scheduling = VLIW (2.7) Multiple-issue, dynamic scheduling, and speculation (2.8)
More informationHandout 2 ILP: Part B
Handout 2 ILP: Part B Review from Last Time #1 Leverage Implicit Parallelism for Performance: Instruction Level Parallelism Loop unrolling by compiler to increase ILP Branch prediction to increase ILP
More informationComputer Architecture Spring 2016
Computer Architecture Spring 2016 Final Review Shuai Wang Department of Computer Science and Technology Nanjing University Computer Architecture Computer architecture, like other architecture, is the art
More informationComputer Architecture: Multi-Core Processors: Why? Prof. Onur Mutlu Carnegie Mellon University
Computer Architecture: Multi-Core Processors: Why? Prof. Onur Mutlu Carnegie Mellon University Moore s Law Moore, Cramming more components onto integrated circuits, Electronics, 1965. 2 3 Multi-Core Idea:
More informationTechniques for Efficient Processing in Runahead Execution Engines
Techniques for Efficient Processing in Runahead Execution Engines Onur Mutlu Hyesoon Kim Yale N. Patt Depment of Electrical and Computer Engineering University of Texas at Austin {onur,hyesoon,patt}@ece.utexas.edu
More informationMultithreaded Processors. Department of Electrical Engineering Stanford University
Lecture 12: Multithreaded Processors Department of Electrical Engineering Stanford University http://eeclass.stanford.edu/ee382a Lecture 12-1 The Big Picture Previous lectures: Core design for single-thread
More informationCopyright 2012, Elsevier Inc. All rights reserved.
Computer Architecture A Quantitative Approach, Fifth Edition Chapter 3 Instruction-Level Parallelism and Its Exploitation 1 Branch Prediction Basic 2-bit predictor: For each branch: Predict taken or not
More informationPortland State University ECE 587/687. The Microarchitecture of Superscalar Processors
Portland State University ECE 587/687 The Microarchitecture of Superscalar Processors Copyright by Alaa Alameldeen and Haitham Akkary 2011 Program Representation An application is written as a program,
More informationLecture 11: SMT and Caching Basics. Today: SMT, cache access basics (Sections 3.5, 5.1)
Lecture 11: SMT and Caching Basics Today: SMT, cache access basics (Sections 3.5, 5.1) 1 Thread-Level Parallelism Motivation: a single thread leaves a processor under-utilized for most of the time by doubling
More informationCSE 820 Graduate Computer Architecture. week 6 Instruction Level Parallelism. Review from Last Time #1
CSE 820 Graduate Computer Architecture week 6 Instruction Level Parallelism Based on slides by David Patterson Review from Last Time #1 Leverage Implicit Parallelism for Performance: Instruction Level
More informationComputer Architecture: Multi-Core Processors: Why? Onur Mutlu & Seth Copen Goldstein Carnegie Mellon University 9/11/13
Computer Architecture: Multi-Core Processors: Why? Onur Mutlu & Seth Copen Goldstein Carnegie Mellon University 9/11/13 Moore s Law Moore, Cramming more components onto integrated circuits, Electronics,
More informationCS6303 Computer Architecture Regulation 2013 BE-Computer Science and Engineering III semester 2 MARKS
CS6303 Computer Architecture Regulation 2013 BE-Computer Science and Engineering III semester 2 MARKS UNIT-I OVERVIEW & INSTRUCTIONS 1. What are the eight great ideas in computer architecture? The eight
More informationPortland State University ECE 588/688. Cray-1 and Cray T3E
Portland State University ECE 588/688 Cray-1 and Cray T3E Copyright by Alaa Alameldeen 2014 Cray-1 A successful Vector processor from the 1970s Vector instructions are examples of SIMD Contains vector
More informationSPECULATIVE MULTITHREADED ARCHITECTURES
2 SPECULATIVE MULTITHREADED ARCHITECTURES In this Chapter, the execution model of the speculative multithreading paradigm is presented. This execution model is based on the identification of pairs of instructions
More informationAdvanced Instruction-Level Parallelism
Advanced Instruction-Level Parallelism Jinkyu Jeong (jinkyu@skku.edu) Computer Systems Laboratory Sungkyunkwan University http://csl.skku.edu EEE3050: Theory on Computer Architectures, Spring 2017, Jinkyu
More informationModule 18: "TLP on Chip: HT/SMT and CMP" Lecture 39: "Simultaneous Multithreading and Chip-multiprocessing" TLP on Chip: HT/SMT and CMP SMT
TLP on Chip: HT/SMT and CMP SMT Multi-threading Problems of SMT CMP Why CMP? Moore s law Power consumption? Clustered arch. ABCs of CMP Shared cache design Hierarchical MP file:///e /parallel_com_arch/lecture39/39_1.htm[6/13/2012
More informationPowerPC 740 and 750
368 floating-point registers. A reorder buffer with 16 elements is used as well to support speculative execution. The register file has 12 ports. Although instructions can be executed out-of-order, in-order
More informationCS425 Computer Systems Architecture
CS425 Computer Systems Architecture Fall 2017 Thread Level Parallelism (TLP) CS425 - Vassilis Papaefstathiou 1 Multiple Issue CPI = CPI IDEAL + Stalls STRUC + Stalls RAW + Stalls WAR + Stalls WAW + Stalls
More informationCS 654 Computer Architecture Summary. Peter Kemper
CS 654 Computer Architecture Summary Peter Kemper Chapters in Hennessy & Patterson Ch 1: Fundamentals Ch 2: Instruction Level Parallelism Ch 3: Limits on ILP Ch 4: Multiprocessors & TLP Ap A: Pipelining
More informationLecture-13 (ROB and Multi-threading) CS422-Spring
Lecture-13 (ROB and Multi-threading) CS422-Spring 2018 Biswa@CSE-IITK Cycle 62 (Scoreboard) vs 57 in Tomasulo Instruction status: Read Exec Write Exec Write Instruction j k Issue Oper Comp Result Issue
More informationSuperscalar Processors Ch 14
Superscalar Processors Ch 14 Limitations, Hazards Instruction Issue Policy Register Renaming Branch Prediction PowerPC, Pentium 4 1 Superscalar Processing (5) Basic idea: more than one instruction completion
More informationSuperscalar Processing (5) Superscalar Processors Ch 14. New dependency for superscalar case? (8) Output Dependency?
Superscalar Processors Ch 14 Limitations, Hazards Instruction Issue Policy Register Renaming Branch Prediction PowerPC, Pentium 4 1 Superscalar Processing (5) Basic idea: more than one instruction completion
More informationProcessor (IV) - advanced ILP. Hwansoo Han
Processor (IV) - advanced ILP Hwansoo Han Instruction-Level Parallelism (ILP) Pipelining: executing multiple instructions in parallel To increase ILP Deeper pipeline Less work per stage shorter clock cycle
More informationThe Processor: Instruction-Level Parallelism
The Processor: Instruction-Level Parallelism Computer Organization Architectures for Embedded Computing Tuesday 21 October 14 Many slides adapted from: Computer Organization and Design, Patterson & Hennessy
More informationLecture: Out-of-order Processors
Lecture: Out-of-order Processors Topics: branch predictor wrap-up, a basic out-of-order processor with issue queue, register renaming, and reorder buffer 1 Amdahl s Law Architecture design is very bottleneck-driven
More informationEN164: Design of Computing Systems Lecture 24: Processor / ILP 5
EN164: Design of Computing Systems Lecture 24: Processor / ILP 5 Professor Sherief Reda http://scale.engin.brown.edu Electrical Sciences and Computer Engineering School of Engineering Brown University
More information" # " $ % & ' ( ) * + $ " % '* + * ' "
! )! # & ) * + * + * & *,+,- Update Instruction Address IA Instruction Fetch IF Instruction Decode ID Execute EX Memory Access ME Writeback Results WB Program Counter Instruction Register Register File
More informationTDT Coarse-Grained Multithreading. Review on ILP. Multi-threaded execution. Contents. Fine-Grained Multithreading
Review on ILP TDT 4260 Chap 5 TLP & Hierarchy What is ILP? Let the compiler find the ILP Advantages? Disadvantages? Let the HW find the ILP Advantages? Disadvantages? Contents Multi-threading Chap 3.5
More informationOut of Order Processing
Out of Order Processing Manu Awasthi July 3 rd 2018 Computer Architecture Summer School 2018 Slide deck acknowledgements : Rajeev Balasubramonian (University of Utah), Computer Architecture: A Quantitative
More informationLecture 11: Out-of-order Processors. Topics: more ooo design details, timing, load-store queue
Lecture 11: Out-of-order Processors Topics: more ooo design details, timing, load-store queue 1 Problem 0 Show the renamed version of the following code: Assume that you have 36 physical registers and
More informationComputer Architecture and Engineering CS152 Quiz #3 March 22nd, 2012 Professor Krste Asanović
Computer Architecture and Engineering CS52 Quiz #3 March 22nd, 202 Professor Krste Asanović Name: This is a closed book, closed notes exam. 80 Minutes 0 Pages Notes: Not all questions are
More informationCPI IPC. 1 - One At Best 1 - One At best. Multiple issue processors: VLIW (Very Long Instruction Word) Speculative Tomasulo Processor
Single-Issue Processor (AKA Scalar Processor) CPI IPC 1 - One At Best 1 - One At best 1 From Single-Issue to: AKS Scalar Processors CPI < 1? How? Multiple issue processors: VLIW (Very Long Instruction
More informationLecture 15: DRAM Main Memory Systems. Today: DRAM basics and innovations (Section 2.3)
Lecture 15: DRAM Main Memory Systems Today: DRAM basics and innovations (Section 2.3) 1 Memory Architecture Processor Memory Controller Address/Cmd Bank Row Buffer DIMM Data DIMM: a PCB with DRAM chips
More informationEECS 570 Final Exam - SOLUTIONS Winter 2015
EECS 570 Final Exam - SOLUTIONS Winter 2015 Name: unique name: Sign the honor code: I have neither given nor received aid on this exam nor observed anyone else doing so. Scores: # Points 1 / 21 2 / 32
More informationPentium IV-XEON. Computer architectures M
Pentium IV-XEON Computer architectures M 1 Pentium IV block scheme 4 32 bytes parallel Four access ports to the EU 2 Pentium IV block scheme Address Generation Unit BTB Branch Target Buffer I-TLB Instruction
More informationCPI < 1? How? What if dynamic branch prediction is wrong? Multiple issue processors: Speculative Tomasulo Processor
1 CPI < 1? How? From Single-Issue to: AKS Scalar Processors Multiple issue processors: VLIW (Very Long Instruction Word) Superscalar processors No ISA Support Needed ISA Support Needed 2 What if dynamic
More informationPortland State University ECE 587/687. Memory Ordering
Portland State University ECE 587/687 Memory Ordering Copyright by Alaa Alameldeen, Zeshan Chishti and Haitham Akkary 2018 Handling Memory Operations Review pipeline for out of order, superscalar processors
More informationSimultaneous Multithreading Architecture
Simultaneous Multithreading Architecture Virendra Singh Indian Institute of Science Bangalore Lecture-32 SE-273: Processor Design For most apps, most execution units lie idle For an 8-way superscalar.
More informationCase Study IBM PowerPC 620
Case Study IBM PowerPC 620 year shipped: 1995 allowing out-of-order execution (dynamic scheduling) and in-order commit (hardware speculation). using a reorder buffer to track when instruction can commit,
More informationA superscalar machine is one in which multiple instruction streams allow completion of more than one instruction per cycle.
CS 320 Ch. 16 SuperScalar Machines A superscalar machine is one in which multiple instruction streams allow completion of more than one instruction per cycle. A superpipelined machine is one in which a
More informationEECS 470 PROJECT: P6 MICROARCHITECTURE BASED CORE
EECS 470 PROJECT: P6 MICROARCHITECTURE BASED CORE TEAM EKA Shaizeen Aga, Aasheesh Kolli, Rakesh Nambiar, Shruti Padmanabha, Maheshwarr Sathiamoorthy Department of Computer Science and Engineering University
More informationLec 25: Parallel Processors. Announcements
Lec 25: Parallel Processors Kavita Bala CS 340, Fall 2008 Computer Science Cornell University PA 3 out Hack n Seek Announcements The goal is to have fun with it Recitations today will talk about it Pizza
More informationHardware-based Speculation
Hardware-based Speculation Hardware-based Speculation To exploit instruction-level parallelism, maintaining control dependences becomes an increasing burden. For a processor executing multiple instructions
More informationLecture 12 Branch Prediction and Advanced Out-of-Order Superscalars
CS 152 Computer Architecture and Engineering CS252 Graduate Computer Architecture Lecture 12 Branch Prediction and Advanced Out-of-Order Superscalars Krste Asanovic Electrical Engineering and Computer
More informationControl Hazards. Prediction
Control Hazards The nub of the problem: In what pipeline stage does the processor fetch the next instruction? If that instruction is a conditional branch, when does the processor know whether the conditional
More informationLimitations of Scalar Pipelines
Limitations of Scalar Pipelines Superscalar Organization Modern Processor Design: Fundamentals of Superscalar Processors Scalar upper bound on throughput IPC = 1 Inefficient unified pipeline
More informationNOW Handout Page 1. Review from Last Time #1. CSE 820 Graduate Computer Architecture. Lec 8 Instruction Level Parallelism. Outline
CSE 820 Graduate Computer Architecture Lec 8 Instruction Level Parallelism Based on slides by David Patterson Review Last Time #1 Leverage Implicit Parallelism for Performance: Instruction Level Parallelism
More informationUNIT I (Two Marks Questions & Answers)
UNIT I (Two Marks Questions & Answers) Discuss the different ways how instruction set architecture can be classified? Stack Architecture,Accumulator Architecture, Register-Memory Architecture,Register-
More informationComputer System Architecture Quiz #2 April 5th, 2019
Computer System Architecture 6.823 Quiz #2 April 5th, 2019 Name: This is a closed book, closed notes exam. 80 Minutes 16 Pages (+2 Scratch) Notes: Not all questions are of equal difficulty, so look over
More informationDynamic Memory Dependence Predication
Dynamic Memory Dependence Predication Zhaoxiang Jin and Soner Önder ISCA-2018, Los Angeles Background 1. Store instructions do not update the cache until they are retired (too late). 2. Store queue is
More informationCMSC22200 Computer Architecture Lecture 8: Out-of-Order Execution. Prof. Yanjing Li University of Chicago
CMSC22200 Computer Architecture Lecture 8: Out-of-Order Execution Prof. Yanjing Li University of Chicago Administrative Stuff! Lab2 due tomorrow " 2 free late days! Lab3 is out " Start early!! My office
More informationWilliam Stallings Computer Organization and Architecture 8 th Edition. Chapter 14 Instruction Level Parallelism and Superscalar Processors
William Stallings Computer Organization and Architecture 8 th Edition Chapter 14 Instruction Level Parallelism and Superscalar Processors What is Superscalar? Common instructions (arithmetic, load/store,
More informationLecture 14: Cache Innovations and DRAM. Today: cache access basics and innovations, DRAM (Sections )
Lecture 14: Cache Innovations and DRAM Today: cache access basics and innovations, DRAM (Sections 5.1-5.3) 1 Reducing Miss Rate Large block size reduces compulsory misses, reduces miss penalty in case
More informationLecture 16: Checkpointed Processors. Department of Electrical Engineering Stanford University
Lecture 16: Checkpointed Processors Department of Electrical Engineering Stanford University http://eeclass.stanford.edu/ee382a Lecture 18-1 Announcements Reading for today: class notes Your main focus:
More informationCopyright 2012, Elsevier Inc. All rights reserved.
Computer Architecture A Quantitative Approach, Fifth Edition Chapter 2 Memory Hierarchy Design 1 Introduction Programmers want unlimited amounts of memory with low latency Fast memory technology is more
More informationDesign and Implementation of a Super Scalar DLX based Microprocessor
Design and Implementation of a Super Scalar DLX based Microprocessor 2 DLX Architecture As mentioned above, the Kishon is based on the original DLX as studies in (Hennessy & Patterson, 1996). By: Amnon
More informationPortland State University ECE 588/688. IBM Power4 System Microarchitecture
Portland State University ECE 588/688 IBM Power4 System Microarchitecture Copyright by Alaa Alameldeen 2018 IBM Power4 Design Principles SMP optimization Designed for high-throughput multi-tasking environments
More informationKaisen Lin and Michael Conley
Kaisen Lin and Michael Conley Simultaneous Multithreading Instructions from multiple threads run simultaneously on superscalar processor More instruction fetching and register state Commercialized! DEC
More informationAdvanced Computer Architecture
Advanced Computer Architecture 1 L E C T U R E 4: D A T A S T R E A M S I N S T R U C T I O N E X E C U T I O N I N S T R U C T I O N C O M P L E T I O N & R E T I R E M E N T D A T A F L O W & R E G I
More informationEN164: Design of Computing Systems Topic 08: Parallel Processor Design (introduction)
EN164: Design of Computing Systems Topic 08: Parallel Processor Design (introduction) Professor Sherief Reda http://scale.engin.brown.edu Electrical Sciences and Computer Engineering School of Engineering
More informationPortland State University ECE 587/687. Memory Ordering
Portland State University ECE 587/687 Memory Ordering Copyright by Alaa Alameldeen and Haitham Akkary 2012 Handling Memory Operations Review pipeline for out of order, superscalar processors To maximize
More informationChecker Processors. Smruti R. Sarangi. Department of Computer Science Indian Institute of Technology New Delhi, India
Advanced Department of Computer Science Indian Institute of Technology New Delhi, India Outline Introduction Advanced 1 Introduction 2 Checker Pipeline Checking Mechanism 3 Advanced Core Checker L1 Failure
More informationExploiting Criticality to Reduce Bottlenecks in Distributed Uniprocessors
Exploiting Criticality to Reduce Bottlenecks in Distributed Uniprocessors Behnam Robatmili Sibi Govindan Doug Burger Stephen W. Keckler beroy@cs.utexas.edu sibi@cs.utexas.edu dburger@microsoft.com skeckler@nvidia.com
More informationCISC 662 Graduate Computer Architecture Lecture 11 - Hardware Speculation Branch Predictions
CISC 662 Graduate Computer Architecture Lecture 11 - Hardware Speculation Branch Predictions Michela Taufer http://www.cis.udel.edu/~taufer/teaching/cis6627 Powerpoint Lecture Notes from John Hennessy
More informationUG4 Honours project selection: Talk to Vijay or Boris if interested in computer architecture projects
Announcements UG4 Honours project selection: Talk to Vijay or Boris if interested in computer architecture projects Inf3 Computer Architecture - 2017-2018 1 Last time: Tomasulo s Algorithm Inf3 Computer
More informationControl Hazards. Branch Prediction
Control Hazards The nub of the problem: In what pipeline stage does the processor fetch the next instruction? If that instruction is a conditional branch, when does the processor know whether the conditional
More information5008: Computer Architecture
5008: Computer Architecture Chapter 2 Instruction-Level Parallelism and Its Exploitation CA Lecture05 - ILP (cwliu@twins.ee.nctu.edu.tw) 05-1 Review from Last Lecture Instruction Level Parallelism Leverage
More informationReal Processors. Lecture for CPSC 5155 Edward Bosworth, Ph.D. Computer Science Department Columbus State University
Real Processors Lecture for CPSC 5155 Edward Bosworth, Ph.D. Computer Science Department Columbus State University Instruction-Level Parallelism (ILP) Pipelining: executing multiple instructions in parallel
More information